1. People throw rubbish into the right bin. Thep keep the environment clean
=> If people throw rubbish into the right bin, they will keep the environment clean.
2. We turn off the tap when brushing the teeth. We save a lot of water.
=> If we turn off the tap when brushing the teeth, we will save a lot of water.
3. What good news!
=> The news are good.
4. It is the first time that I have ever talked to a foreigner.
=> I have not talked to a foreigner before.
5. We've never tasted fish and chips before.
=> It is the first time we have tasted fish and chips.